// First Calculation - Add all the digits of the ID number in the odd positions
// (except for the last number, which is the control digit):
int calc1 = first + third + fith + seventh + ninth + eleventh;

// Second Calculation - Take all the even digits as one number and multiply that by 2
string calc2a = two + four + six + eight + ten + twelve;
int calc2 = atoi(calc2a.c_str());
calc2 = calc2 * 2;

// Third Calculation - Add the digits of this number together (in calc2)
// Convert answer in calc2 back to a string and then add them together
string calc3a = calc2;

// First Calculation - Add all the digits of the ID number in the odd positions
// (except for the last number, which is the control digit):
int calc1 = first + third + fith + seventh + ninth + eleventh;

// Second Calculation - Take all the even digits as one number and multiply that by 2
string calc2a = two + four + six + eight + ten + twelve;
int calc2 = atoi(calc2a.c_str());
calc2 = calc2 * 2;

// Third Calculation - Add the digits of this number together (in calc2)
// Convert answer in calc2 back to a string and then add them together
char b[50];
string calc3a;
sprintf(b,"%d",calc2);// C-style string formed without null
calc3a += b;
string numberz[20];
int numbers[20];
int calc3 = 0;
int stringLength = calc3a.size();